18WuD2x

38 arc cosecant • area code
radians or degrees, corresponding to a given
cosecant.
arc cosine Abbreviated arc cos or cos –1 . 1. The inverse
of the cosine function. 2. The angle, in radians
or degrees, corresponding to a given cosine.
arc cotangent Abbreviated arc cot or cot –1 . 1. The
inverse of the cotangent function. 2. The angle, in
radians or degrees, corresponding to a given
cotangent.
arc failure 1. Damage to, and/or failure of, insulation
or a dielectric as a result of ARCOVER. 2.
Failure of make-and-break contacts through
damage caused by arcover.
arc function An inverse trigonometric function. See
ARC COSECANT, ARC COSINE, ARC COTAN-
GENT, ARC SECANT, ARC SINE, and ARC TAN-
GENT.
arc furnace A high-temperature electric furnace in
which heat is produced by one or more electrical
arcs.
architecture The functional design elements of a
computer—especially the components of the central
processing unit (CPU) and the manner in
which these elements interact.
archived file A computer file stored on some
backup medium, such as magnetic tape, diskette,
or CD-ROM (compact disk, read-only memory),
rather than being held on the hard disk.
Such a file will be apart from the operating system’s
catalog of current files, but can be reconstituted
as needed.
archives A complete, periodically updated set of
ARCHIVED FILES.
arcing See ARCOVER.
arcing contacts Make-and-break contacts between
which an arc occurs when they are separated.
arcing ring A metal ring placed around an insulator
in a high-voltage electrical system. This keeps
an arc from charring or breaking the insulator.
arcing time The elapsed time between the breaking
of contacts and the end of the arc between the
contacts.
arc lamp An electric lamp in which a brilliant arc
jumps between the tips of two rods (originally carbon).
arc length The length along a given arc, usually a
part of the circumference of a circle. If the circle
has circumference C and the arc measures x degrees,
then the arc length is Cx/360 units.
arc minute See MINUTE.
arc oscillation Oscillations that can occur when
opening relay contacts arc.
arcover The occurrence of an electrical ARC between
electrodes, contacts, or capacitive plates.
arcover voltage The voltage at which disruptive
discharge occurs, typically accompanied by an
arc.
arc resistance The ability of a material, usually a
dielectric, to resist damage from arcing. This
property is commonly expressed as the length of
time between the start of the arc and the establishment
of a conductive path through the material.
arc secant Abbreviated arc sec or sec –1 . 1. The inverse
of the secant function. 2. The angle, in radians
or degrees, that corresponds to a given
secant.
arc second See SECOND.
arc sensor A device for detecting visible arcs and
excessive reflected power in microwave systems.
arc sine Abbreviated arc sin or sin –1 . 1. The inverse
of the sine function. 2. The angle, in radians or
degrees, that corresponds to a given sine.
arc suppression Extinguishing an arc discharge.
Disruptive arcs in electronic circuits are suppressed
by means of auxiliary diodes or resistorcapacitor
networks.
arc-suppressor diode A semiconductor diode used
to prevent arcing between make-and-break contacts.
arc tangent Abbreviated arc tan or tan –1 . 1. The
inverse of the tangent function. 2. The angle, in
radians or degrees, corresponding to a given tangent.
arcthrough The puncturing of a material by an
arc.
area code In the United States, a three-digit
number that indicates the location, according to
specified assigned districts, of a telephone sub-